Rupture constraint mechanism

ABSTRACT

Apparatus and system for containing a rupture of a duct. The apparatus includes an air-permeable sheet, such as a wide-weave fiberglass sheet. The air-permeable sheet includes a strap arranged on a first side of the sheet such that it forms diamond-shaped patterns along a longitudinal axis. The strap can be made of a tight-weave fiberglass. Laterally-spaced corners of the diamond-shaped patterns include connection members that can be engaged to affix the strap and the air-permeable sheet around a duct. Various aspects include an air-impermeable air barrier surrounding the wide-weave fiberglass sheet and strap. The air barrier can include a window that directs air from a ruptured duct. Various aspects can be used on a bleed-air duct of an aircraft. The window of the air barrier can be aimed at a temperature sensor. A valve can close the bleed-air duct if the temperature sensor detects a high temperature leak.

BACKGROUND

The present application relates to a rupture constraint mechanism, andmore specifically, to a rupture constraint mechanism for ahigh-temperature environment.

SUMMARY

According to an aspect, an apparatus includes a sheet that includes afirst side and a second opposing side. The apparatus also includes astrap arranged on the first side of the air-permeable sheet. The strapcomprises a tight weave material. The strap includes a first pluralityof connection members and a second plurality of connection membersarranged along the strap such that the first plurality of connectionmembers can couple to respective ones of the second plurality ofconnection members when the sheet is disposed on a pressurized gasvessel.

According to an aspect, an apparatus includes an air-permeablefiberglass sheet that includes a first side and a second opposing side.The air-permeable fiberglass sheet defines a longitudinal axis. Theapparatus also includes a strap arranged on the first side of theair-permeable fiberglass sheet. The strap comprises tight-weavefiberglass. The strap extends along the longitudinal axis from a startpoint on the longitudinal axis to an end point on the longitudinal axis.The strap criss-crosses the longitudinal axis to form a plurality ofdiamond-shaped patterns on the first side of the air-permeablefiberglass sheet. Opposing laterally-spaced corners of eachdiamond-shaped pattern are located a lateral width away from thelongitudinal axis. The apparatus also includes first connection membersattached to the strap at respective first laterally-spaced corners ofthe diamond-shaped pattern on a first side of the longitudinal axis. Theapparatus also includes second connection members attached to the strapat respective second laterally-spaced corners of the diamond-shapedpattern on a second side of the longitudinal axis. The second connectionmembers are configured to be coupled to the first connection members tostrap the air-permeable fiberglass sheet around a duct.

According to an aspect, a method for isolating a pressurized gas vesselincludes arranging a sheet around a pressure vessel. The sheet includesa strap arranged on an outward-facing side of the sheet. The strapcomprises a tight weave material. The strap includes a first pluralityof connection members and a second plurality of connection membersarranged along the strap. The method also includes connecting respectiveones of the first plurality of connection members to respective ones ofthe second plurality of connection members.

According to an aspect, a method includes arranging a strap on a firstside of a sheet. The strap includes a first plurality of connectionmembers and a second plurality of connection members arranged on thestrap such that the first plurality of connection members can couple torespective ones of the second plurality of connection members when thesheet is disposed on a pressurized gas vessel. The method also includesattaching the arranged strap to the sheet.

According to an aspect, a system for isolating a duct includes a ruptureconstraint mechanism. The rupture constraint mechanism includes anair-permeable fiberglass sheet that includes a first side and a secondopposing side. The air-permeable fiberglass sheet defines a longitudinalaxis. The rupture constraint mechanism also includes a strap arranged onthe first side of the air-permeable fiberglass sheet. The strapcomprises tight-weave fiberglass. The strap extends along thelongitudinal axis from a start point on the longitudinal axis to an endpoint on the longitudinal axis. The strap criss-crosses the longitudinalaxis to form a plurality of diamond-shaped patterns on the first side ofthe air-permeable fiberglass sheet. Opposing laterally-spaced corners ofeach diamond-shaped pattern are located a lateral width away from thelongitudinal axis. The rupture constraint mechanism also includes firstconnection members attached to the strap at respective firstlaterally-spaced corners of the diamond-shaped pattern on a first sideof the longitudinal axis. The rupture constraint mechanism also includesecond connection members attached to the strap at respective secondlaterally-spaced corners of the diamond-shaped pattern on a second sideof the longitudinal axis. The second connection members are configuredto be coupled to the first connection members to strap the air-permeablefiberglass sheet around a duct. The system also includes an air barrierthat wraps around the ballistic sheet on the duct. The air barrierincludes an insulation blanket. The air barrier also includes a fastenermechanism that fastens a first edge of the insulation blanket relativeto a second opposing edge of the insulation blanket around the duct.

According to an aspect, an aircraft includes a wing that includes atleast one of a composite skin and a composite wing spar. The aircraftalso includes a gas turbine engine attached to the wing and a bleed airduct from the gas turbine engine passing through the wing. The aircraftalso includes a removable rupture constraint mechanism wrapped around atleast a portion of the bleed air duct. The removable rupture constraintmechanism includes an air-permeable fiberglass sheet that includes afirst side and a second opposing side. The air-permeable fiberglasssheet defines a longitudinal axis. The rupture constraint mechanism alsoincludes a strap arranged on the first side of the air-permeablefiberglass sheet. The strap comprises tight-weave fiberglass. The strapextends along the longitudinal axis from a start point on thelongitudinal axis to an end point on the longitudinal axis. The strapcriss-crosses the longitudinal axis to form a plurality ofdiamond-shaped patterns on the first side of the air-permeablefiberglass sheet. Opposing laterally-spaced corners of eachdiamond-shaped pattern are located a lateral width away from thelongitudinal axis. The rupture constraint mechanism also includes firstconnection members attached to the strap at respective firstlaterally-spaced corners of the diamond-shaped pattern on a first sideof the longitudinal axis. The rupture constraint mechanism also includessecond connection members attached to the strap at respective secondlaterally-spaced corners of the diamond-shaped pattern on a second sideof the longitudinal axis. The second connection members are coupled tothe first connection members to strap the air-permeable fiberglass sheetaround the bleed air duct. The aircraft also includes an air barrierwrapped around the ballistic sheet on the duct. The air barrier includesan insulation blanket. The air barrier also includes a fastenermechanism that fastens a first edge of the insulation blanket relativeto a second opposing edge of the insulation blanket around the bleed airduct.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A is a top view of a rupture constraint mechanism according tovarious aspects, wherein the wrap is laid flat;

FIG. 1B is a perspective view of the rupture constraint mechanism ofFIG. 1A;

FIG. 2 is a partial top view of an aircraft, wherein certain interiorfeatures of the aircraft are shown in dashed line;

FIG. 3A is a top view of the rupture constraint mechanism of FIG. 1Aaccording to various aspects, wherein the wrap is laid flat, and whereinweave arresting strips are omitted for clarity;

FIG. 3B is a top detail view of a portion of a laterally-spaced cornerof a diamond-shaped pattern on the rupture constraint mechanism of FIG.3A, wherein a connection member is shown;

FIG. 3C is a top detail view of a portion of a laterally-spaced cornerof a diamond-shaped pattern on the rupture constraint mechanism of FIG.3A, wherein a connection member is shown;

FIG. 4 is a side view of the rupture constraint mechanism of FIG. 1A,wherein the wrap is laid flat;

FIG. 5 is a detail schematic side view of a portion of the ruptureconstraint mechanism of FIG. 1A, wherein ends of a strap overlap and aresewn to a mat and to each other;

FIG. 6A is a perspective view of the rupture constraint mechanism ofFIG. 1A arranged to be wrapped around a duct;

FIG. 6B is a partial perspective view of the rupture constraintmechanism of FIG. 1A wrapped around the duct, and wherein an air barrieris shown in partial cross-section wrapped around the duct and therupture constraint mechanism;

FIG. 7A is a top view of a strap arrangement for a rupture constraintmechanism according to various aspects; and

FIG. 7B is a side view of the strap arrangement of FIG. 7A withfasteners included.

DETAILED DESCRIPTION

In the following, reference is made to aspects presented in thisdisclosure. However, the scope of the present disclosure is not limitedto specific described aspects. Instead, any combination of the followingfeatures and elements, whether related to different aspects or not, iscontemplated to implement and practice contemplated aspects.Furthermore, although aspects disclosed herein may achieve advantagesover other possible solutions or over the prior art, whether or not aparticular advantage is achieved by a given aspect is not limiting ofthe scope of the present disclosure. Thus, the following aspects,features, and advantages are merely illustrative and are not consideredelements or limitations of the appended claims except where explicitlyrecited in a claim(s). Likewise, reference to “the invention” shall notbe construed as a generalization of any inventive subject matterdisclosed herein and shall not be considered to be an element orlimitation of the appended claims except where explicitly recited in aclaim(s).

In various applications, ducts transport high-temperature and/orhigh-pressure gas. Occasionally, such ducts suffer failures, and gasescaping from the rupture can damage structures around the ducts. FIG. 2illustrates an example of a high-temperature, high-pressure duct in anaircraft 200. FIG. 2 depicts a portion of a fuselage 202 and a wing 204of the aircraft 200. The wing 204 includes structural members, such as aspar 206. The skin of the wing and/or structural members, such as thespar 206, can be made from a composite material, such as carbon fiberreinforced plastic (CFRP). The aircraft 200 is powered by a gas turbineengine 208 that is suspended from the wing 204. A bleed air duct 210transports high-temperature, high-pressure air bled from the gas turbineengine 208 to one or more pneumatic systems 212 (e.g., a pneumaticgenerator, an Environmental Conditioning System, or the like), whichuses the air from the bleed air duct 210 to operate various systemsonboard the aircraft 200. In the event the bleed air duct 210 ruptures,escaping high-temperature, high-pressure air could damage the compositespar 206, the composite wing skin, and/or other composite structureswithin the wing 204.

To mitigate problems associated with a duct rupture, the bleed air duct210 can include an air barrier wrapped there around. The air barrier mayinclude a fabric, such as a silicone-infused fabric, wrap that issubstantially air impermeable and that can withstand the hightemperature of the bleed air. In low temperature operations, the airbarrier could be a plastic sheet or other substantially air impermeablematerial. The air barrier can include a gap, a seam, a window, or thelike through which air escaping from a duct rupture can be directed.However, a rupture of the bleed air duct 210 could damage the airbarrier, causing hot bleed air to escape from the bleed air duct 210through a compromised portion of the air barrier. Such escaping bleedair could impinge on the composite structures in the wing 204, causingdamage.

In various aspects described herein, an air-permeable rupture constraintmechanism is applied around a duct, such as the bleed air duct 210,which can absorb kinetic energy from a rupture of the duct. Asubstantially impermeable air barrier that can direct air escaping fromthe rupture can surround the rupture constraint mechanism. The ruptureconstraint mechanism and the air barrier are removable from the duct,enabling periodic inspections of the duct. The air-permeable ruptureconstraint mechanism can prevent the rupturing duct from compromisingthe air barrier. In various aspects, a temperature sensor can bearranged near a window or other gap in the air barrier. In the event ofa duct failure, high temperature gas will escape through the window andimpinge on the temperature sensor, causing an increase in an indicatedtemperature. The increased indicated temperature can cause a valve to beclosed to stop gas flow through the ruptured duct.

FIGS. 1A and 1B illustrate a rupture constraint mechanism 100 accordingto various aspects. The rupture constraint mechanism 100 includes anair-permeable sheet 102. For example, the air-permeable sheet 102 maycomprise a wide-weave fiberglass, such as Owens Corning® wide weavefiberglass. The air-permeable sheet 102 may be generally rectangular inshape. In various instances, the air-permeable sheet 102 may have ashape other than rectangular (e.g., a circular shape or an oval shape).For purposes of explanation, an axis 108 is shown on the air-permeablesheet 102. The wide weave fiberglass may be loosely woven, giving thefabric properties that diminish the ability to retain stitches in theevent of a rupture. To address the reduced holding strength of a stitchin a wide-weave fabric in the event of a rupture, the rupture constraintmechanism 100 can include a strap 106 (e.g., a tight-weave strap)attached to the air-permeable sheet 102. The strap 106 can be arrangedin a crisscross manner over the axis 108 that results in adiamond-shaped pattern 130 on the air-permeable sheet 102. In variousinstances, the strap could be made from a high-strength fiberglass, suchas S-glass fiberglass.

The high-strength fiberglass strap can have a tighter weave than the airpermeable fiberglass that comprises the air-permeable sheet 102. As aresult, the strap 106 may not be air permeable, but the diamond-shapedpattern 130 provides spacing between portions of the strap 106 throughwhich air from a ruptured pipe can escape. The strap 106 can be attachedto the air-permeable sheet 102 in any variety of ways, including bypermanent or releasable means. For example, the strap 106 could beattached to the air-permeable sheet 102 using tape or glue. In oneaspect, the high-strength fiberglass of the strap 106 can hold a stitch,so that the strap 106 can be sewn to the air-permeable sheet 102. Thestitches, described in greater detail below, or other attachment meansenable the air-permeable sheet 102 to be positioned relative to thestrap 106. Laterally-spaced corners 126 and 128 of each diamond-shapedpattern 130 can include connection members 110 and 112, respectively.The connection members 110 and 112 may comprise male and femaleconnection members, respectively, that mate together to connect a firstlaterally-spaced corner 126 to an opposing second laterally-spacedcorner 128. For example, the connection members 110 and 112 couldinclude female buckle member and male buckle members, respectively. Invarious instances, the connection members may be made of plastic. Invarious other embodiments, the connection members may be made of ametal, such as a steel alloy, an aluminum alloy, brass, or the like. Anexample of the connection members is the GT COBRA® connector made byAustriAlpin and ITW Nexus North America.

Referring to FIG. 6A, the rupture constraint mechanism 100 can be placedover a duct 300 (e.g., the bleed air duct 210 of the aircraft 200, shownin FIG. 2). The rupture constraint mechanism 100 can then be wrappedaround the duct 300 as indicated by arrows Z. Referring to FIG. 6B, asthe rupture constraint mechanism 100 is wrapped around the duct 300, theconnection members 110 and 112 can be engaged to secure the ruptureconstraint mechanism 100 around the duct 300. FIG. 6B also shows apartial cutaway of an air barrier 400 (also referred to as an insulationblanket) surrounding the rupture constraint mechanism 100. The airbarrier 400 includes a substantially air-impermeable mat 402 (e.g., madeof a silicone-infused fabric), that can contain and direct air thatescapes from the duct 300. The air barrier 400 may be secured around therupture constraint mechanism 100 with a fastener mechanism, such aslaces 406, passing through apertures 410 arranged along opposing edgesof the substantially air-impermeable mat 402. The air barrier 400 mayinclude an outlet to direct escaping air in a particular direction. Forexample, the air barrier 400 may include a window 408 or aperturethrough which air from the ruptured duct 300 can escape. As anotherexample, the air barrier 400 may include a gap 404 between the opposingedges of the substantially air-impermeable mat 402. Air escaping fromthe ruptured duct 300 could pass through the gap 404.

Referring to FIGS. 1A-1B, 3A-3C, and 5, as discussed above, the strap106 is arranged on the air-permeable sheet 102 in a diamond-shapedpattern 130, and the strap 106 can be sewn to the air-permeable sheet102. For example, S-Glass fiberglass can be used as stitches 134. Invarious embodiments, the strap 106 can comprise a single, continuouspiece of strap material. Referring to FIG. 1A, at a starting location114 along the axis 108, a section “A” of the strap 106 can be laid outperpendicular to the axis 108. A male connection member 112 can beplaced on the strap. For example, referring to FIG. 3C, the maleconnection member 112 could include a slot 136 through which the strap106 can be fitted. After the male connection member 112 is placed on thestrap 106, the strap 106 can be folded over to form section “B” at anangle relative to section “A.” For example, section “B” may be arrangedat an angle between around 10° and 20° relative to section “A.” Asanother example, section “B” may be arranged at an angle of around 15°relative to section “A.” A female connection member 110 can be placed onthe strap 106. For example, referring to FIG. 3B, the female connectionmember 110 could include a slot 132 through which the strap 106 can befitted. After the female connection member 110 is placed on the strap106, the strap 106 can be folded over at an angle to form section “C”relative to section “B.” The angle between sections “B” and “C” can bedouble the angle between sections “A” and “B.” For example, the anglebetween sections “B” and “C” may be between around 20° and 40°. Asanother example, the angle between sections “B” and “C” may be around30°. A female connection member 110 can be placed on the strap 106, andthe strap 106 can be folded over to form section “D.” Section “D” can bearranged relative to section “C” at the same angle as the angle betweensections “B” and “C.” The strap 106 can continue to be laid out byforming sections “E,” “F,” “G,” “H,” “I,” “J,” and “K” in a similarmanner to sections “B” and “C,” described above. Female and maleconnection members 110 and 112, respectively, can be alternately placedbetween each section. After section “K” is formed, the strap has reachedan ending location 116 on the axis 108. At the ending location 116, amale connection member 112 can be placed on the strap 106, and the strap106 can be folded at an angle to form section “L” perpendicular to theaxis 108. The angle between sections “K” and “L” may be the same as theangle between sections “A” and “B.”

After section “L” is formed, a female connection member 110 can beplaced on the strap 106, and the strap can be folded at an angle to formsection “M.” The angle between sections “L” and “M” can be the same asthe angle between sections “K” and “L.” After section “M,” a maleconnection member 112 can be placed on the strap 106, and the strap 106can be folded over at an angle to form section “N.” The angle betweensections “M” and “N” can be the same as the angle between sections “B”and “C,” discussed above. After section “N” is formed, a femaleconnection member 110 can be placed on the strap 106, and the strap 106can be folded at an angle to form section “O.” The angle betweensections “N” and “O” can be the same as the angle between sections “M”and “N.” The strap 106 can continue to be laid out by forming sections“P,” “Q,” “R,” “S,” “T,” “U,” and “V” in a similar manner to sections“M” and “N” and sections “N” and “O” described above. Female and maleconnection members 110 and 112, respectively, can be alternately placedbetween each section. After section “V,” the strap has returned to thestarting location 114 on the axis 108. At the starting location 114, afemale connection member 110 can be placed on the strap 106, and thestrap 106 can be folded at an angle to form section “W” perpendicular tothe axis 108. The angle between sections “V” and “W” can be the same asthe angle between sections “A” and “B,” discussed above. As shown fromthe side in FIG. 5, at least a portion of section “W” of the strap 106overlaps with at least a portion of section “A” of the strap 106.

The strap 106, when laid out as described above, forms diamond-shapedpatterns 130 along the axis 108. Female connection members 110 arelocated at first laterally-spaced corners 126 of the diamond-shapedpatterns 130 and male connection members 112 are located at secondlaterally-spaced corners 128 of the diamond-shaped patterns 130. Invarious aspects, both male connection members 112 and female connectionmembers 110 can be located on laterally-spaced corners on a first sideof the longitudinal axis so long as the opposite connection member typeis located at opposing laterally-spaced corners. For example, theconnection member between sections “C” and “D” in FIG. 1A could be afemale connection member 110 so long as the connection member betweensections “T” and “U” is a male connection member 112. Referring to FIGS.3A-3C, the sections “A” through “W” of the strap 106 can be sewn to theair-permeable sheet 102 (e.g., using stitches of S-glass fiberglassthread). The stitches 134 can extend along the length of each section,except for a portion at the laterally-spaced corners 126, 128. Forexample, referring to FIG. 3B, in various aspects, the axis 108 can bearranged relative to the air-permeable sheet 102 such that the firstlaterally-spaced corners 126 and the female connection members 110extend past an edge 122 of the air-permeable sheet 102. In that case,the stitches 134 can extend close to the edge 122 of the air-permeablesheet 102. A portion of the strap 106 at the laterally-spaced cornerhaving a lateral dimension D1 does not have stitching 134. The lack ofstitching proximate to the laterally-spaced corner 126 provides freedomof movement for the female connection member 110 located at thelaterally-spaced corner 126, enabling the female connection members 110to be manipulated for connection to corresponding male connectionmembers 112. Referring now to FIG. 3C, the axis 108 can be arrangedrelative to the air-permeable sheet 102 such that the secondlaterally-spaced corners 128 and the male connection members 112 arelocated over the air-permeable sheet 102. In such aspects, the stitches134 can extend to a lateral dimension D2 of the second lateral corner128. The lack of stitching proximate to the laterally-spaced corner 128provides freedom of movement for the male connection member 112 locatedat the laterally-spaced corner 128, enabling the male connection member112 to be manipulated for connection to a corresponding femaleconnection member 110.

Referring to FIG. 5, as discussed above, sections “A” and “W” of thestrap 106 overlap. Stitching 134 can be sewn through sections “A” and“W” of the strap 106 and through the air-permeable sheet 102. Thestitching 134 can anchor sections “A” and “W” to the air-permeable sheet102 and also connect sections “A” and “W” of the strap 106 together.

In various aspects, the strap 106 may include several separate sectionsof strap material that are sewn together. For example, referring to FIG.1A, a first portion of the strap 106 may include sections “A,” “B,” and“V.” A second portion of the strap 106 may include sections “B” and “C.”A third portion of the strap 106 may include sections “V” and “U.” Thefirst portion of the strap 106 can be placed on the air-permeable sheet102 and sewn in place. The second portion of the strap 106 can be placedon the air-permeable sheet 102 such that section “B” of the secondportion overlaps with section “B” of the first portion. Then, the two“B” sections can be sewn to the air-permeable sheet 102 and to eachother. Similarly, the third portion of the strap 106 can be placed onthe air-permeable sheet 102 such that section “V” of the third portionoverlaps with section “V” of the first portion. Then, the two “V”sections can be sewn to the air-permeable sheet 102 and to each other.Additional portions can be laid on the air-permeable sheet 102 and sewntogether in a similar manner.

Referring again to FIGS. 3A-3C, in one aspect, the air-permeable sheet102 has a length L of 72 inches and a width of about 27.5 inches. Theaxis 108 is offset from a centerline of the air-permeable sheet 102 byabout 5 inches and a width W1 of the diamond-shaped patterns 130 isabout 21.5 inches. As a result, the first laterally-spaced corners 126of the diamond-shaped patterns 130 extend about 2 inches past the edge122 of the air-permeable sheet 102. The dimension D1 of the portion ofthe diamond-shaped patterns 130 at the laterally-spaced corners 126without stitching 134 can be slightly greater than about 2 inches. Also,the second laterally-spaced corners 128 of the diamond-shaped patterns130 are located an inboard distance W2 of 8 inches. The dimension D2portion of the diamond-shaped patterns 130 at the laterally-spacedcorners 128 without stitching 134 can be approximately 2 inches. Aspacing S between adjacent laterally-spaced corners 126 or 128 can beapproximately 8 inches. The strap 106 can have a width of approximately1.5 inches.

Referring to FIGS. 1A, 1B, and 4, the air-permeable sheet 102 caninclude one or more weave arresting strips 104. In various aspects, theweave arresting strips 104 are aligned with the axis 108. As shown inFIG. 4, each weave arresting strip 104 includes a pleat 140. The pleat140 is formed by creating a first fold 144 and a second fold 142 in theair-permeable sheet 102. The first fold 144 and the second fold 142 canbe substantially parallel to the axis 108. A first strip of tape 146(e.g., S-glass fiberglass tape) is applied to a pleat 140 on a firstside 152 of the air-permeable sheet 102 and a second strip of tape 148is applied to the pleat on a second side 150 of the air-permeable sheet102. The first strip of tape 146 and the second strip of tape 148 can besewn to the pleat 140 (e.g., with S-glass fiberglass stitches). Similarto the strap 106, the first strip of tape 146 and the second strip oftape 148 make the weave arresting strips 104 less air-permeable thanremaining portions of the air-permeable sheet 102. However, the weavearresting strips 104 are localized features, and any air that escapesfrom a rupture of a duct can flow around the weave arresting strips 104.In the event of a rupture of a duct, the air-permeable sheet 102 at thelocation of the rupture may tear or rip. Momentum of the rupturing ductmaterial and/or air flowing out of the duct may cause individual strandsof the air-permeable sheet 102 to unravel. The weave arresting strips104 can provide extra strand retention to the air-permeable sheet 102,which may stop such strands from unraveling further Although the weavearresting strips 104 shown in the figures are aligned with the axis 108,they can also be aligned in other directions, such as perpendicular tothe axis 108 or at another angle.

FIGS. 7A and 7B illustrate another aspect of the strap 106 for an airpermeable mat. In this aspect, the connection members are replaced byconnection rods 170 and 172. A first connection rod 170 is passedthrough the strap 106 at first laterally-spaced corners 128 of thediamond-shaped patterns 130 where the strap 106 folds back on itself. Asecond connection rod is passed through the strap 106 at secondlaterally-spaced corners 126 of the diamond-shaped pattern where thestrap 106 folds back on itself. As shown in FIG. 7B, when the strap 106is wrapped around a duct 300, the connection rods 170 and 172 arearranged close together. In some aspects, the connection rods 170 and172 may be spaced apart. In various other aspects, the connection rods170 and 172 may be touching. Connection clips 174 can be attached to theconnection rods 170 and 172 to secure the connection rods 170 and 172together and retain the strap 106 around the duct 300. In other aspects,a combination of different connection means is used.

As discussed above, in various aspects, the axis 108 of the strap 106can be offset from a centerline of the air-permeable sheet 102.Referring again to FIG. 3A, such an offset can form a width W2 of theair-permeable sheet 102 to the side of the strap 106. The width W2 ofthe air-permeable sheet 102 may ease installation of the ruptureconstraint mechanism 100 around a duct 300. For example, the ruptureconstraint mechanism 100 shown in FIG. 1A could be arranged on the duct300 such that the male connection members 112 are positioned at the topof the duct 300. The width W2 of air permeable mat 100 could be drapedover one side of the duct 300, wherein gravity will pull the width W2into contact with the duct 300. The female connection members 110 can bepulled around an opposite side of the high pressure duct to engage themale connection members 112. The width W2 laying flat on the duct 300can ensure that the air-permeable sheet 102 lays flat against the duct300 rather than bunching up while the connection members 110 and 112 arebeing engaged. Also, the width W2 of the air-permeable sheet 102provides an overlapping portion of the rupture constraint mechanism 100that ensures that no gap exists in the air-permeable sheet 102. Forexample, in the example shown in FIG. 3A, the edges 122 and 124 of themay overlap by an amount equal to W2−D1.

Referring again to FIG. 2, in use in an aircraft 200, the ruptureconstraint mechanism (e.g., rupture constraint mechanism 100) canprotect an air barrier (e.g., the air barrier 400 shown in FIG. 6B) fromdamage caused by a rupture in a bleed air duct 210. The air barrier caninclude a window 218 that is oriented toward a temperature sensor 214.As discussed above, in various aspects, the window 218 could be anopening in the air barrier (e.g., the substantially air-impermeable mat402 shown in FIG. 6B). In various aspects, the window 218 could be anair-permeable section in the air barrier (e.g., the substantiallyair-impermeable mat 402). In the event of a rupture of the bleed airduct 210, escaping air can pass through the air permeable mat of therupture constraint mechanism and through the window 218 in the airbarrier. The escaping bleed air, which is hot, will cause thetemperature sensor 214 to sense an elevated temperature. If the sensedtemperature exceeds a threshold temperature, a valve 216 between thebleed air duct 210 and the gas turbine engine 208 can be closed to stopair flow through the bleed air duct 210. In various aspects, the eventof the sensed temperature exceeding a threshold temperature couldilluminate a warning light in the flight deck of the aircraft, and apilot may take steps to close the valve. For example, a pilot mayoperate one or more switches in the flight deck to close the valve 216.In various other aspects, a computer onboard the aircraft 200 mayautomatically close the valve 216 in the event the sensed temperatureexceeds a threshold temperature. By closing the valve 216, the compositestructures of the wing 204 may be saved from damage caused byhigh-temperature air escaping from a ruptured bleed air duct 210.

The rupture constraint mechanism 100 described above can be easilyremoved and reinstalled from a duct to facilitate periodic maintenanceand inspection of the duct or to facilitate inspection related to afault indication. For example, referring to the aircraft 200 of FIG. 2,the aircraft may provide pilots or maintenance personnel with a lowpneumatic pressure warning. In such an instance, a flight may be delayeduntil the cause of the low pneumatic pressure (e.g., a leak) is foundand fixed. Maintenance personnel can quickly remove the ruptureconstraint mechanism 100 by removing the air barrier and then undoingthe connection members 110 and 112. After the high pressure duct 210 hasbeen inspected, the rupture constraint mechanism 100 can be quicklyreinstalled.

In the aspects described above, the diamond-shaped patterns 130 of thestrap 106 provide circumferential support for the air-permeable sheet102 as well as longitudinal support for the air-permeable sheet 102. Putdifferently, the strap 106 holds the air-permeable sheet 102 around aduct and provides support in the event of a duct rupture. Thediamond-shaped patterns 130 in the strap 106 interconnect thelongitudinally spaced-apart connection members 110 and 112. In the eventof a duct rupture that may cause a tear in the air-permeable sheet 102,the longitudinal interconnections between connection members 110 and 112by the diamond-shaped patterns 130 can prevent the torn-apart sectionsof the air-permeable sheet 102 from moving apart from each other in thelongitudinal direction and the circumferential direction along the duct.This application contemplates other aspects that secure an air-permeablemat around a duct and that also provide longitudinal stability andintegrity. For example, a strap (e.g., strap 106) could be arranged inother patterns, such as a checkered pattern, a circular net pattern, orany other interconnected pattern.

The descriptions of the various aspects herein have been presented forpurposes of illustration, but are not intended to be exhaustive orlimited to the aspects disclosed. Many modifications and variations willbe apparent to those of ordinary skill in the art without departing fromthe scope and spirit of the described aspects. The terminology usedherein was chosen to best explain the principles of the aspects, thepractical application or technical improvement over technologies foundin the marketplace, or to enable others of ordinary skill in the art tounderstand the aspects disclosed herein.

While the foregoing is directed to aspects of the present invention,other and further aspects of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

What is claimed is:
 1. An apparatus, comprising: a sheet that includes afirst side and a second opposing side; and a strap arranged on the firstside of the sheet, the strap comprising a first weave material, thestrap including a first plurality of connection members and a secondplurality of connection members arranged along the strap such that thefirst plurality of connection members can couple to respective ones ofthe second plurality of connection members when the sheet is disposed ona pressurized gas vessel, the strap extending along an axis on the sheetfrom a start point to an end point and criss-crossing the axis to form aplurality of diamond-shaped patterns on the first side of the sheet,wherein opposing laterally-spaced corners of each diamond pattern arelocated a lateral width away from the axis, the strap folding over atthe laterally-spaced corners, the first plurality of connection membersattached to the strap at respective folds at the first laterally-spacedcorners, and the second plurality of connection members attached to thestrap at respective folds at the second laterally-spaced corners.
 2. Theapparatus of claim 1, wherein the strap comprises an S-glass fiberglass.3. An apparatus, comprising: a sheet that includes a first side and asecond opposing side, wherein the sheet comprises an air-permeable weavefiberglass, wherein the air-permeable sheet comprises a weave arrestingstrip, wherein the weave arresting strip comprises: a pleat formed inthe air-permeable sheet; a first strip of tape arranged on a first sideof the pleat; a second strip of tape arranged on a second side of thepleat; and stitching that engages the pleat, the first strip of tape,and the second strip of tape; and a strap arranged on the first side ofthe sheet, wherein the strap comprises a first weave material, andwherein the strap includes a first plurality of connection members and asecond plurality of connection members arranged along the strap suchthat the first plurality of connection members can couple to respectiveones of the second plurality of connection members when the sheet isdisposed on a pressurized gas vessel.
 4. The apparatus of claim 1,wherein the strap is sewn to the air-permeable sheet with stitches. 5.The apparatus of claim 1, wherein the first plurality of connectionmembers comprise a plurality of male buckle members, wherein the secondplurality of connection members comprise a plurality of female bucklemembers, and wherein the plurality of male buckle members engagerespective ones of the plurality of female buckle members to couple thefirst connection members to the second connection members.
 6. Theapparatus of claim 5, wherein the plurality of male buckle membersdisengage the respective ones of the plurality of female buckle membersto decouple the first connection members from the second connectionmembers.
 7. An apparatus, comprising: a sheet that includes a first sideand a second opposing side; and a strap arranged on the first side ofthe sheet, the strap comprising: a first weave material; a firstplurality of connection members and a second plurality of connectionmembers arranged along the strap such that the first plurality ofconnection members can couple to respective ones of the second pluralityof connection members when the sheet is disposed on a pressurized gasvessel, and wherein the first plurality of connection members comprise afirst connection rod engaged with at least two first laterally-spacedcorners, wherein the second plurality of connection members comprise asecond connection rod engaged with at least second laterally-spacedcorners; and at least one connection clip configured to attach to thefirst connection rod and the second connection rod.
 8. A system forisolating a duct, the system comprising: a rupture constraint mechanismcomprising: an air-permeable fiberglass sheet that includes a first sideand a second opposing side, the air-permeable fiberglass sheet defininga longitudinal axis; a strap arranged on the first side of theair-permeable fiberglass sheet, the strap comprising weaved fiberglass,the strap extending along the longitudinal axis from a start point onthe longitudinal axis to an end point on the longitudinal axis, thestrap criss-crossing the longitudinal axis to form a plurality ofdiamond-shaped patterns on the first side of the air-permeablefiberglass sheet, wherein opposing laterally-spaced corners of eachdiamond-shaped pattern are located a lateral width away from thelongitudinal axis; first connection members attached to the strap atrespective first laterally-spaced corners of the diamond-shaped patternon a first side of the longitudinal axis; and second connection membersattached to the strap at respective second laterally-spaced corners ofthe diamond-shaped pattern on a second side of the longitudinal axis,the second connection members configured to be coupled to the firstconnection members to strap the air-permeable fiberglass sheet around aduct; and an air barrier that wraps around the rupture constraintmechanism on the duct, the air barrier comprising: an insulationblanket; and a fastener mechanism that fastens a first edge of theinsulation blanket relative to a second opposing edge of the insulationblanket around the duct.
 9. The system of claim 8, wherein the strapfolds over at the laterally-spaced corners, wherein the first connectionmembers are attached to the strap at respective folds at the firstlaterally-spaced corners, and wherein the second connection members areattached to the strap at respective folds at the second laterally-spacedcorners.
 10. The system of claim 8, wherein the air-permeable fiberglasssheet comprises a second weave fiberglass, wherein the weave fiberglassof the strap is tighter than the weave of the air-permeable fiberglasssheet.
 11. The system of claim 8, wherein the strap comprises an S-glassfiberglass.
 12. The system of claim 8, wherein the air-permeablefiberglass sheet comprises a weave arresting strip, wherein the weavearresting strip comprises: a pleat formed in the air-permeablefiberglass sheet; a first strip of fiberglass tape arranged on a firstside of the pleat; a second strip of fiberglass tape arranged on asecond side of the pleat; and fiberglass stitching engaging the pleat,the first strip of fiberglass tape, and the second strip of fiberglasstape.
 13. The system of claim 8, wherein the strap is sewn to theair-permeable fiberglass sheet with fiberglass stitches.
 14. The systemof claim 8, wherein the first connection members comprise a plurality ofmale buckle members, wherein the second connection members comprise aplurality of female buckle members, and wherein the plurality of malebuckle members engage respective ones of the plurality of female bucklemembers to couple the first connection members to the second connectionmembers.
 15. The system of claim 8, wherein the first connection memberscomprise a first connection rod engaged with at least two of the firstlaterally-spaced corners, wherein the second connection members comprisea second connection rod engaged with at least two of the secondlaterally-spaced corners; and further comprising at least one connectionclip configured to attach to the first connection rod and the secondconnection rod.
 16. An aircraft, comprising: a wing that includes atleast one of a composite skin and a composite wing spar; a gas turbineengine attached to the wing; a bleed air duct from the gas turbineengine passing through the wing; a removable rupture constraintmechanism wrapped around at least a portion of the bleed air duct, theremovable rupture constraint mechanism comprising: an air-permeablefiberglass sheet that includes a first side and a second opposing side,the air-permeable fiberglass sheet defining a longitudinal axis; a straparranged on the first side of the air-permeable fiberglass sheet, thestrap comprising weaved fiberglass, the strap extending along thelongitudinal axis from a start point on the longitudinal axis to an endpoint on the longitudinal axis, the strap criss-crossing thelongitudinal axis to form a plurality of diamond-shaped patterns on thefirst side of the air-permeable fiberglass sheet, wherein opposinglaterally-spaced corners of each diamond-shaped pattern are located alateral width away from the longitudinal axis; first connection membersattached to the strap at respective first laterally-spaced corners ofthe diamond-shaped pattern on a first side of the longitudinal axis; andsecond connection members attached to the strap at respective secondlaterally-spaced corners of the diamond-shaped pattern on a second sideof the longitudinal axis, the second connection members coupled to thefirst connection members to strap the air-permeable fiberglass sheetaround the bleed air duct; and an air barrier wrapped around the ruptureconstraint mechanism on the duct, the air barrier comprising: aninsulation blanket; and a fastener mechanism that fastens a first edgeof the insulation blanket relative to a second opposing edge of theinsulation blanket around the bleed air duct.
 17. The aircraft of claim16, further comprising a temperature sensor, wherein the air barrierdefines a gap between the first edge of the insulation blanket and thesecond opposing edge of the insulation blanket, and wherein the airbarrier is wrapped around the ballistic sheet and the duct such that thegap is oriented toward the temperature sensor.
 18. The aircraft of claim17, further comprising a valve arranged between the gas turbine engineand the bleed air duct, wherein the valve is configured to automaticallyclose in the event that the temperature sensor indicates a temperatureabove a threshold temperature.